Backlight driver for Tabletkiosk Sahara TouchIT-213 Tablet PC

...

drivers/video/backlight/kb3886_bl.c new file +1 -0

+void kb3886_bl_set_intensity(int intensity)

...

I believe the mdelay()s could be converted to the preferable msleep()?

Hi,

Quoted 1 line

I believe the mdelay()s could be converted to the preferable msleep()?

thank you for the remark. I have changed the mdelay to msleep in my patch, reapplied it to the current Linus tree, built a kernel, installed it on my computer and tested it. It works perfectly as you surely expected. The corrected patch is included here.

BTW: I have noticed that some other drivers in video/backlight still use
mdelay: ili9320.c, locomolcd.c and vgg2432a4.c.

claudio

Signed-off-by Claudio Nieder <[email protected]>

---
 drivers/video/backlight/Kconfig     |    7 +
 drivers/video/backlight/Makefile    |    1 +
 drivers/video/backlight/kb3886_bl.c |  218 +++++++++++++++++++++++++++++++++++
 3 files changed, 226 insertions(+), 0 deletions(-)

drivers/video/backlight/Kconfig +7 -0

index 452b770..bc65541 100644
@@ -164,3 +164,10 @@ config BACKLIGHT_MBP_NVIDIA
          If you have an Apple Macbook Pro with Nvidia graphics hardware say Y
 	 to enable a driver for its backlight
 
+config BACKLIGHT_SAHARA
+	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
+	depends on BACKLIGHT_CLASS_DEVICE && X86
+	default y
+	help
+	  If you have a Tabletkiosk Sahara Touch-iT, say y to enable the
+	  backlight driver.

drivers/video/backlight/Makefile +1 -0

index b405aac..f4a1183 100644
@@ -16,4 +16,5 @@ obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
 obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o
 obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
+obj-$(CONFIG_BACKLIGHT_SAHARA)	+= kb3886_bl.o
 

drivers/video/backlight/kb3886_bl.c new file +28 -0

new file mode 100644
index 0000000..60eec06
@@ -0,0 +1,218 @@
+/*
+ *  Backlight Driver for the KB3886 Backlight
+ *
+ *  Copyright (c) 2007 Claudio Nieder
+ *
+ *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/delay.h>
+
+
+/*
+ * The following is what corgi has in arch/arm/mach-pxa/corgi.c and
+ * corgi_lcd.c. On kernelnebwies it was suggested I put the platform_device
+ * code in my driver.
+ */

drivers/video/backlight/kb3886_bl.c new file +31 -0

+{
+	mutex_lock(&bl_mutex);
+	intensity = intensity&0xff;
+	outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
+	msleep(10);
+	outb(KB3886_PWM0_WRITE, KB3886_IO);
+	msleep(10);
+	outb(intensity, KB3886_IO);
+	mutex_unlock(&bl_mutex);
+}
+
+struct kb3886bl_machinfo {
+	int max_intensity;
+	int default_intensity;
+	int limit_mask;
+	void (*set_bl_intensity)(int intensity);
+};
+
+static struct kb3886bl_machinfo kb3886_bl_machinfo = {
+	.max_intensity = 0xff,
+	.default_intensity = 0xa0,
+	.limit_mask = 0x7f,
+	.set_bl_intensity = kb3886_bl_set_intensity,
+};
+
+static struct platform_device kb3886bl_device = {
+	.name		= "kb3886-bl",
+	.dev		= {
+		.platform_data	= &kb3886_bl_machinfo,
+	},
+	.id		= -1,

drivers/video/backlight/kb3886_bl.c new file +63 -0

+
+/*
+ * Back to driver
+ */
+
+static int kb3886bl_intensity;
+static struct backlight_device *kb3886_backlight_device;
+static struct kb3886bl_machinfo *bl_machinfo;
+
+static unsigned long kb3886bl_flags;
+#define KB3886BL_SUSPENDED     0x01
+#define KB3886BL_BATTLOW       0x02
+
+static int kb3886bl_send_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+
+	if (bd->props.power != FB_BLANK_UNBLANK)
+		intensity = 0;
+	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
+		intensity = 0;
+	if (kb3886bl_flags & KB3886BL_SUSPENDED)
+		intensity = 0;
+	if (kb3886bl_flags & KB3886BL_BATTLOW)
+		intensity &= bl_machinfo->limit_mask;
+
+	bl_machinfo->set_bl_intensity(intensity);
+
+	kb3886bl_intensity = intensity;
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int kb3886bl_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	kb3886bl_flags |= KB3886BL_SUSPENDED;
+	backlight_update_status(bd);
+	return 0;
+}
+
+static int kb3886bl_resume(struct platform_device *pdev)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	kb3886bl_flags &= ~KB3886BL_SUSPENDED;
+	backlight_update_status(bd);
+	return 0;
+}
+#else
+#define kb3886bl_suspend	NULL
+#define kb3886bl_resume		NULL
+#endif
+
+static int kb3886bl_get_intensity(struct backlight_device *bd)
+{
+	return kb3886bl_intensity;
+}
+
+/*
+ * Called when the battery is low to limit the backlight intensity.
+ * If limit==0 clear any limit, otherwise limit the intensity

drivers/video/backlight/kb3886_bl.c new file +66 -0

+
+
+static struct backlight_ops kb3886bl_ops = {
+	.get_brightness = kb3886bl_get_intensity,
+	.update_status  = kb3886bl_send_intensity,
+};
+
+static int kb3886bl_probe(struct platform_device *pdev)
+{
+	struct kb3886bl_machinfo *machinfo = pdev->dev.platform_data;
+
+	bl_machinfo = machinfo;
+	if (!machinfo->limit_mask)
+		machinfo->limit_mask = -1;
+
+	kb3886_backlight_device = backlight_device_register("kb3886-bl",
+		&pdev->dev, NULL, &kb3886bl_ops);
+	if (IS_ERR (kb3886_backlight_device))
+		return PTR_ERR(kb3886_backlight_device);
+
+	platform_set_drvdata(pdev, kb3886_backlight_device);
+
+	kb3886_backlight_device->props.max_brightness = machinfo->max_intensity;
+	kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
+	kb3886_backlight_device->props.brightness = machinfo->default_intensity;
+	backlight_update_status(kb3886_backlight_device);
+
+	return 0;
+}
+
+static int kb3886bl_remove(struct platform_device *pdev)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver kb3886bl_driver = {
+	.probe		= kb3886bl_probe,
+	.remove		= kb3886bl_remove,
+	.suspend	= kb3886bl_suspend,
+	.resume		= kb3886bl_resume,
+	.driver		= {
+		.name	= "kb3886-bl",
+	},
+};
+
+static int __init kb3886_init(void)
+{
+	sahara_init();
+	return platform_driver_register(&kb3886bl_driver);
+}
+
+static void __exit kb3886_exit(void)
+{
+	platform_driver_unregister(&kb3886bl_driver);
+}
+
+module_init(kb3886_init);
+module_exit(kb3886_exit);
+
+MODULE_AUTHOR("Claudio Nieder <[email protected]>");
+MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
+MODULE_LICENSE("GPL");

Signature · 10 lines

1.4.4.4


-- 
Claudio Nieder, Talweg 6, CH-8610 Uster, Tel +4179 357 6743, www.claudio.ch
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Poking at random ports isn't very nice. Is it possible to autodetect this tablet PC ? Has it specific PCI ids or usefull DMI table ?

static ?

Why do you need this wrapper ?

This function is unused. Looks like you copied it from corgi_bl.c where it is called from platform code.

Hi,

Quoted 2 lines

Poking at random ports isn't very nice. Is it possible to autodetect this tablet PC ? Has it specific PCI ids or usefull DMI table ?

I didn't find anthing with lspci but can detect through DMI - if you are interested you find the dmidecode output at the end of
http://claudio.ch/Bin/viewcvs.cgi/Config/sysinfo_touchIt213?rev=294 - and do it in a similar way as in mbp_nvidia_bl.c. Have done it in the included patch.

Looking at the macbook driver I see it is much simpler and shorter than mine which I derived from corgi_bl.c. No platform driver, no probe, remove, suspend and resume.

Why is one much simpler than the other? Is functionality missing in the MacBook driver or is the corgi one just (historically) overblown? If I could safely reduce my driver to be as simple as the macbook one I would be more than happy to do it.

Quoted 1 line

static ?

Fixed.

Quoted 1 line

Why do you need this wrapper ?

When I studied the corgi_bl driver I noticed that some stuff is done in the driver itself and then there is the "platform stuff". I didn't know how to handle it and was given the suggestion to put the platform stuff also in the driver which I did but tried to keep that textually separate. Thus the separate sahara_init. Yet I had to call it in kb3886_init otherwise nothing else would do. I surely didn't fully understand what I was doing when I wrote that. Have simplified it as suggested.

If all this can be simplified even more, like is done in macbook driver, that would be great.

Quoted 2 lines

This function is unused. Looks like you copied it from corgi_bl.c where it is called from platform code.

Fixed, i.e. removed.

Below the fixed patch, correcting all mistakes reported by Andrey.

Signed-off-by Claudio Nieder <[email protected]>

---
 drivers/video/backlight/Kconfig     |    7 +
 drivers/video/backlight/Makefile    |    1 +
 drivers/video/backlight/kb3886_bl.c |  214 +++++++++++++++++++++++++++++++++++
 3 files changed, 222 insertions(+), 0 deletions(-)

drivers/video/backlight/Kconfig +7 -0

index 452b770..bc65541 100644
@@ -164,3 +164,10 @@ config BACKLIGHT_MBP_NVIDIA
          If you have an Apple Macbook Pro with Nvidia graphics hardware say Y
 	 to enable a driver for its backlight
 
+config BACKLIGHT_SAHARA
+	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
+	depends on BACKLIGHT_CLASS_DEVICE && X86
+	default y
+	help
+	  If you have a Tabletkiosk Sahara Touch-iT, say y to enable the
+	  backlight driver.

drivers/video/backlight/Makefile +1 -0

index b405aac..f4a1183 100644
@@ -16,4 +16,5 @@ obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
 obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o
 obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
+obj-$(CONFIG_BACKLIGHT_SAHARA)	+= kb3886_bl.o
 

drivers/video/backlight/kb3886_bl.c new file +87 -0

new file mode 100644
index 0000000..1a1d8aa
@@ -0,0 +1,214 @@
+/*
+ *  Backlight Driver for the KB3886 Backlight
+ *
+ *  Copyright (c) 2007-2008 Claudio Nieder
+ *
+ *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/dmi.h>
+
+/*
+ * The following is what corgi has in arch/arm/mach-pxa/corgi.c and
+ * corgi_lcd.c. On kernelnebwies it was suggested I put the platform_device
+ * code in my driver.
+ */
+
+#define KB3886_PARENT 0x64
+#define KB3886_IO 0x60
+#define KB3886_ADC_DAC_PWM 0xC4
+#define KB3886_PWM0_WRITE 0x81
+#define KB3886_PWM0_READ 0x41
+
+static DEFINE_MUTEX(bl_mutex);
+
+static void kb3886_bl_set_intensity(int intensity)
+{
+	mutex_lock(&bl_mutex);
+	intensity = intensity&0xff;
+	outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
+	msleep(10);
+	outb(KB3886_PWM0_WRITE, KB3886_IO);
+	msleep(10);
+	outb(intensity, KB3886_IO);
+	mutex_unlock(&bl_mutex);
+}
+
+struct kb3886bl_machinfo {
+	int max_intensity;
+	int default_intensity;
+	int limit_mask;
+	void (*set_bl_intensity)(int intensity);
+};
+
+static struct kb3886bl_machinfo kb3886_bl_machinfo = {
+	.max_intensity = 0xff,
+	.default_intensity = 0xa0,
+	.limit_mask = 0x7f,
+	.set_bl_intensity = kb3886_bl_set_intensity,
+};
+
+static struct platform_device kb3886bl_device = {
+	.name		= "kb3886-bl",
+	.dev		= {
+		.platform_data	= &kb3886_bl_machinfo,
+	},
+	.id		= -1,
+};
+
+static struct platform_device *devices[] __initdata = {
+	&kb3886bl_device,
+};
+
+/*
+ * Back to driver
+ */
+
+static int kb3886bl_intensity;
+static struct backlight_device *kb3886_backlight_device;
+static struct kb3886bl_machinfo *bl_machinfo;
+
+static unsigned long kb3886bl_flags;
+#define KB3886BL_SUSPENDED     0x01
+#define KB3886BL_BATTLOW       0x02
+

drivers/video/backlight/kb3886_bl.c new file +107 -0

+	{ }
+};
+
+static int kb3886bl_send_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+
+	if (bd->props.power != FB_BLANK_UNBLANK)
+		intensity = 0;
+	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
+		intensity = 0;
+	if (kb3886bl_flags & KB3886BL_SUSPENDED)
+		intensity = 0;
+	if (kb3886bl_flags & KB3886BL_BATTLOW)
+		intensity &= bl_machinfo->limit_mask;
+
+	bl_machinfo->set_bl_intensity(intensity);
+
+	kb3886bl_intensity = intensity;
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int kb3886bl_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	kb3886bl_flags |= KB3886BL_SUSPENDED;
+	backlight_update_status(bd);
+	return 0;
+}
+
+static int kb3886bl_resume(struct platform_device *pdev)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	kb3886bl_flags &= ~KB3886BL_SUSPENDED;
+	backlight_update_status(bd);
+	return 0;
+}
+#else
+#define kb3886bl_suspend	NULL
+#define kb3886bl_resume		NULL
+#endif
+
+static int kb3886bl_get_intensity(struct backlight_device *bd)
+{
+	return kb3886bl_intensity;
+}
+
+static struct backlight_ops kb3886bl_ops = {
+	.get_brightness = kb3886bl_get_intensity,
+	.update_status  = kb3886bl_send_intensity,
+};
+
+static int kb3886bl_probe(struct platform_device *pdev)
+{
+	struct kb3886bl_machinfo *machinfo = pdev->dev.platform_data;
+
+	bl_machinfo = machinfo;
+	if (!machinfo->limit_mask)
+		machinfo->limit_mask = -1;
+
+	kb3886_backlight_device = backlight_device_register("kb3886-bl",
+		&pdev->dev, NULL, &kb3886bl_ops);
+	if (IS_ERR (kb3886_backlight_device))
+		return PTR_ERR(kb3886_backlight_device);
+
+	platform_set_drvdata(pdev, kb3886_backlight_device);
+
+	kb3886_backlight_device->props.max_brightness = machinfo->max_intensity;
+	kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
+	kb3886_backlight_device->props.brightness = machinfo->default_intensity;
+	backlight_update_status(kb3886_backlight_device);
+
+	return 0;
+}
+
+static int kb3886bl_remove(struct platform_device *pdev)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver kb3886bl_driver = {
+	.probe		= kb3886bl_probe,
+	.remove		= kb3886bl_remove,
+	.suspend	= kb3886bl_suspend,
+	.resume		= kb3886bl_resume,
+	.driver		= {
+		.name	= "kb3886-bl",
+	},
+};
+
+static int __init kb3886_init(void)
+{
+	if (!dmi_check_system(kb3886bl_device_table))
+		return -ENODEV;
+
+	platform_add_devices(devices, ARRAY_SIZE(devices));
+	return platform_driver_register(&kb3886bl_driver);
+}
+
+static void __exit kb3886_exit(void)

Signature · 5 lines

1.4.4.4

claudio
-- 
Claudio Nieder, Talweg 6, CH-8610 Uster, Tel +4179 357 6743, www.claudio.ch

These two empty initializers are not needed.

Now let's add module alias to ensure driver autoloading. IMHO the line below should do the trick:

MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");